diff --git a/hack/lib/test_lib.sh b/hack/lib/test_lib.sh
index ee68081be8d..c0f12b058a3 100644
--- a/hack/lib/test_lib.sh
+++ b/hack/lib/test_lib.sh
@@ -48,3 +48,37 @@ function trap_add() {
                 fatal "unable to add to trap ${trap_add_name}"
     done
 }
+
+# add_go_mod_replace adds a "replace" directive from $1 to $2 with an
+# optional version version $3 to the current working directory's go.mod file.
+function add_go_mod_replace() {
+	local from_path="${1:?first path in replace statement is required}"
+	local to_path="${2:?second path in replace statement is required}"
+	local version="${3:-}"
+
+	if [[ ! -d "$to_path" && -z "$version" ]]; then
+		echo "second replace path $to_path requires a version be set because it is not a directory"
+		exit 1
+	fi
+	if [[ ! -e go.mod ]]; then
+		echo "go.mod file not found in $(pwd)"
+		exit 1
+	fi
+
+	# If $to_path is a directory, it needs a `go.mod` file that specifies the
+	# module name to make the go toolchain happy.
+	#
+	# TODO: remove the below if statement once
+	# https://github.com/operator-framework/operator-sdk/pull/1566 is merged,
+	# which updates the SDK to use go modules.
+	if [[ -d "${to_path}" && ! -e "${to_path}/go.mod" ]]; then
+		echo "module ${from_path}" > "${to_path}/go.mod"
+		trap_add "rm ${to_path}/go.mod" EXIT
+	fi
+	# Do not use "go mod edit" so formatting stays the same.
+	local replace="replace ${from_path} => ${to_path}"
+	if [[ -n "$version" ]]; then
+		replace="$replace $version"
+	fi
+	echo "$replace" >> go.mod
+}
diff --git a/hack/tests/e2e-ansible.sh b/hack/tests/e2e-ansible.sh
index 2f39dabb3a0..4cbaeb7bfb6 100755
--- a/hack/tests/e2e-ansible.sh
+++ b/hack/tests/e2e-ansible.sh
@@ -133,18 +133,9 @@ then
     exit 1
 fi
 
-# Right now, SDK projects still need a vendor directory, so run `go mod vendor`
-# to pull down the deps specified by the scaffolded `go.mod` file.
+add_go_mod_replace "github.com/operator-framework/operator-sdk" "$ROOTDIR"
 go mod vendor
 
-# Use the local operator-sdk directory as the repo. To make the go toolchain
-# happy, the directory needs a `go.mod` file that specifies the module name,
-# so we need this temporary hack until we update the SDK repo itself to use
-# go modules.
-echo "module github.com/operator-framework/operator-sdk" > $ROOTDIR/go.mod
-trap_add 'rm $ROOTDIR/go.mod' EXIT
-go mod edit -replace=github.com/operator-framework/operator-sdk=$ROOTDIR
-
 operator-sdk build "$DEST_IMAGE"
 
 deploy_operator
diff --git a/hack/tests/e2e-helm.sh b/hack/tests/e2e-helm.sh
index d1a8332a735..0cb6f432672 100755
--- a/hack/tests/e2e-helm.sh
+++ b/hack/tests/e2e-helm.sh
@@ -128,18 +128,9 @@ then
     exit 1
 fi
 
-# Right now, SDK projects still need a vendor directory, so run `go mod vendor`
-# to pull down the deps specified by the scaffolded `go.mod` file.
+add_go_mod_replace "github.com/operator-framework/operator-sdk" "$ROOTDIR"
 go mod vendor
 
-# Use the local operator-sdk directory as the repo. To make the go toolchain
-# happy, the directory needs a `go.mod` file that specifies the module name,
-# so we need this temporary hack until we update the SDK repo itself to use
-# go modules.
-echo "module github.com/operator-framework/operator-sdk" > $ROOTDIR/go.mod
-trap_add 'rm $ROOTDIR/go.mod' EXIT
-go mod edit -replace=github.com/operator-framework/operator-sdk=$ROOTDIR
-
 operator-sdk build "$DEST_IMAGE"
 
 deploy_operator
diff --git a/test/e2e/memcached_test.go b/test/e2e/memcached_test.go
index 3660fc27f2e..65040cbf965 100644
--- a/test/e2e/memcached_test.go
+++ b/test/e2e/memcached_test.go
@@ -17,7 +17,6 @@ package e2e
 import (
 	"bytes"
 	"context"
-	"errors"
 	"fmt"
 	"io/ioutil"
 	"os"
@@ -35,8 +34,8 @@ import (
 	"github.com/operator-framework/operator-sdk/pkg/test/e2eutil"
 
 	"github.com/ghodss/yaml"
+	"github.com/pkg/errors"
 	"github.com/prometheus/prometheus/util/promlint"
-	"github.com/rogpeppe/go-internal/modfile"
 	v1 "k8s.io/api/core/v1"
 	apierrors "k8s.io/apimachinery/pkg/api/errors"
 	"k8s.io/apimachinery/pkg/apis/meta/v1/unstructured"
@@ -114,18 +113,24 @@ func TestMemcached(t *testing.T) {
 			// stub go.mod into the local SDK repo referred to in
 			// memcached-operator's go.mod, which allows go to recognize
 			// the local SDK repo as a module.
-			sdkModPath := filepath.Join(replace.repo, "go.mod")
-			err = ioutil.WriteFile(sdkModPath, []byte("module "+sdkRepo), fileutil.DefaultFileMode)
-			if err != nil {
-				t.Fatalf("Failed to write main repo go.mod file: %v", err)
-			}
-			defer func() {
-				if err = os.RemoveAll(sdkModPath); err != nil {
-					t.Fatalf("Failed to remove %s: %v", sdkModPath, err)
+			sdkModPath := filepath.Join(filepath.FromSlash(replace.repo), "go.mod")
+			if _, err = os.Stat(sdkModPath); err != nil && os.IsNotExist(err) {
+				err = ioutil.WriteFile(sdkModPath, []byte("module "+sdkRepo), fileutil.DefaultFileMode)
+				if err != nil {
+					t.Fatalf("Failed to write main repo go.mod file: %v", err)
 				}
-			}()
+				defer func() {
+					if err = os.RemoveAll(sdkModPath); err != nil {
+						t.Fatalf("Failed to remove %s: %v", sdkModPath, err)
+					}
+				}()
+			}
+		}
+		modBytes, err := insertGoModReplace(t, sdkRepo, replace.repo, replace.ref)
+		if err != nil {
+			t.Fatalf("Failed to insert go.mod replace: %v", err)
 		}
-		writeGoModReplace(t, sdkRepo, replace.repo, replace.ref)
+		t.Logf("go.mod: %v", string(modBytes))
 	}
 
 	cmdOut, err = exec.Command("go", "mod", "vendor").CombinedOutput()
@@ -306,30 +311,21 @@ func getGoModReplace(t *testing.T, localSDKPath string) goModReplace {
 	}
 }
 
-func writeGoModReplace(t *testing.T, repo, path, sha string) {
+func insertGoModReplace(t *testing.T, repo, path, sha string) ([]byte, error) {
 	modBytes, err := ioutil.ReadFile("go.mod")
 	if err != nil {
-		t.Fatalf("Failed to read go.mod: %v", err)
-	}
-	modFile, err := modfile.Parse("go.mod", modBytes, nil)
-	if err != nil {
-		t.Fatalf("Failed to parse go.mod: %v", err)
-	}
-	if err = modFile.AddReplace(repo, "", path, sha); err != nil {
-		s := ""
-		if sha != "" {
-			s = " " + sha
-		}
-		t.Fatalf(`Failed to add "replace %s => %s%s: %v"`, repo, path, s, err)
+		return nil, errors.Wrap(err, "failed to read go.mod")
 	}
-	if modBytes, err = modFile.Format(); err != nil {
-		t.Fatalf("Failed to format go.mod: %v", err)
+	sdkReplace := fmt.Sprintf("replace %s => %s", repo, path)
+	if sha != "" {
+		sdkReplace = fmt.Sprintf("%s %s", sdkReplace, sha)
 	}
+	modBytes = append(modBytes, []byte("\n"+sdkReplace)...)
 	err = ioutil.WriteFile("go.mod", modBytes, fileutil.DefaultFileMode)
 	if err != nil {
-		t.Fatalf("Failed to write updated go.mod: %v", err)
+		return nil, errors.Wrap(err, "failed to write go.mod before replacing SDK repo")
 	}
-	t.Logf("go.mod: %v", string(modBytes))
+	return modBytes, nil
 }
 
 func memcachedLeaderTest(t *testing.T, f *framework.Framework, ctx *framework.TestCtx) error {